Field of the Invention
The invention relates to an apparatus for catalytic combustion of exhaust gases in an exhaust system, particularly for an exhaust system of an internal combustion engine, and preferably for Otto engines, having at least a first and a second honeycomb body through which a fluid can flow in succession, the honeycomb bodies each having a multiplicity of channels and at least one of the honeycomb bodies being heatable, and a plurality of support elements each having at least one end, the support elements extending between the first honeycomb body and the second honeycomb body, joining them mechanically, and protruding at least part way into the respective honeycomb body in the region of the at least one end.
Published International Application WO 92/13636, corresponding to U.S. application Ser. No. 08/101,493, filed Aug. 2, 1993, discloses a honeycomb body having a plurality of disks being braced against one another. The honeycomb body has at least two disks which are spaced apart from one another and disposed one after the other in terms of the flow direction of an exhaust gas, and each of them has channels. Near a flow direction ,axis, supports are provided by which the disks are joined together and braced against one another. However, the manufacture of such a honeycomb body proves to be difficult, since the location of the supports must be defined accurately beforehand in both parts of the honeycomb body. That is disadvantageous since the exact structure of two honeycomb bodies can only be calibrated with great difficulty, and there will always be at least slight deviations. That is especially true because the honeycomb bodies include wound layers of sheet metal, and during winding the exact location of receptacles for the supports cannot be predicted precisely. In the honeycomb body described above, a few supports must be disposed primarily near the flow axis, but under certain resonance conditions that is not always enough to reliably brace the entire cross-sectional area of the honeycomb body.
Honeycomb bodies, particularly those that are electrically heatable, are also known from Published International Application WO 92/18245; Published International Application WO 89/10471, corresponding to allowed U.S. application Ser. No. 07/604,199, filed, Oct. 25, 1990 and U.S. application Ser. No. 08/054,348, filed Apr. 27, 1993; Published International Application WO 93/20339; and Published International Application WO 92/00190, corresponding to U.S. application Ser. No. 08/101,455, filed, Aug. 2, 1993.